Securitized Debt - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Debt Instrument [Line Items]
Gains (losses) on extinguishment of debt	$ 4,039,000	$ (2,897,000)	$ 6,348,000	$ (2,897,000)
Variable Interest Entities, Primary Beneficiary | Non-Agency RMBS | Securitized Loans
Debt Instrument [Line Items]
Principal balance	$ 110,000,000		$ 110,000,000		$ 110,000,000
Weighted average cost of financing (as a percent)	6.70%		6.70%		6.70%
Variable Interest Entities, Primary Beneficiary | Securitized debt | Securitized Loans
Debt Instrument [Line Items]
Principal balance	$ 8,800,000,000		$ 8,800,000,000		$ 7,900,000,000
Weighted average cost of financing (as a percent)	3.30%		3.30%		2.80%
Acquired securitized debt collateral outstanding principal balance	$ 212,000,000	$ 0	$ 551,000,000	$ 0
Repurchase of non retained secured debt	208,000,000		545,000,000
Gains (losses) on extinguishment of debt	$ 4,000,000		$ 6,000,000